Quantity long-term data storage has long been accomplished on such media as magnetic tape and rigid magnetic discs, as well as punched paper cards and tape; however, the magnetic disc, mainly used heretofore have largely been of the rigid type, typically mounted in a semi-permanent manner in a spaced parallel array within a protective enclosure, and involving numerous refinements and precautionary refinements, including for example non-contacting "flying" magnetic heads and the like. Nonetheless, such discs have certain advantages compared to other media and even compared to magnetic tape, including extremely short access times and other such features. However, until recently such advantages have been obtained only at relatively high expense, and with other inconvenience such as the requirement of meticulous and careful handling, etc.
More recently, the advent, at least in a practical sense, of flexible disc recording technologies have shown the advantages of the inexpensive limp or "floppy" flexible discs, typically made by coating the opposite sides of a thin highly flexible sheet of polymeric or other plastic film with magnetic oxide, with the coated disc being only on the order of 3 to 4 mils thick. This limply flexible disc is then permanently enclosed within a close-fitting sleeve-like protective outer envelope, in which it may be rotated while the envelope is held in position. The envelope has an enlarged central opening for access to the center of the disc, and also has a radial slot opening, by which a magnetic head may access the face of the disc while the same is rotated. For example, the disc structure may be substantially shown in U.S. Pat. No. 3,668,658, and one form of recorder/reproducer device for such a device is shown in U.S. Pat. No. 3,678,481.
Previously-known recorders using flexible discs of the type just noted have not been sufficiently developed so as to have all, or even most of, the exceptionally great operational flexibility made possible by the flexible disc recording media; for example, such recorders have been limited to the use of a single disc and would only operate to record on one side of the disc, despite the presence on both sides of suitable magnetizable media, recording on both sides being possible only by physically withdrawing and inverting the disc. Furthermore, loading of the discs to the recording heads has been cumbersome and at times ineffective and even defective, involving the use of a variety of different types and arrangements of pressure pads and other such elements.